This is acia-tmpl.c in view mode; [Download] [Up]
/*
*
* This file is part of Commodore 64 emulator.
* See README for copyright notice
*
* ACIA 6551 rs232 emulation
*
* Written by
* Andre Fachat (a.fachat@physik.tu-chemnitz.de)
*
*/
#include <stdio.h>
#include "resources.h"
#include "cmdline.h"
#include "vice.h"
#include "types.h"
#include "vmachine.h"
#include "interrupt.h"
#include "rs232.h"
#include "acia.h"
#undef DEBUG
#define ACIA_TICKS 21111
static int fd = -1;
static int intx = 0; /* indicates that a transmit is currently ongoing */
static int irq = 0;
static BYTE cmd;
static BYTE ctrl;
static BYTE rxdata; /* data that has been received last */
static BYTE txdata; /* data prepared to send */
static BYTE status;
/******************************************************************/
static int myacia_device;
static int myacia_irq;
static int myacia_set_device(resource_value_t v) {
if(fd>=0) {
fprintf(stderr, "MYACIA: device open, change effective only after "
"close!\n");
}
myacia_device = (int) v;
return 0;
}
static int myacia_set_irq(resource_value_t v) {
if((int)v) {
myacia_irq = IK_NMI;
} else {
myacia_irq = IK_IRQ;
}
return 0;
}
static resource_t resources[] = {
{ "MyAciaDev", RES_INTEGER, (resource_value_t) MyDevice,
(resource_value_t *) & myacia_device, myacia_set_device },
{ "MyAciaIrq", RES_INTEGER, (resource_value_t) MyIrq,
(resource_value_t *) & myacia_irq, myacia_set_irq },
{ NULL }
};
int myacia_init_resources(void) {
return resources_register(resources);
}
static cmdline_option_t cmdline_options[] = {
{ "-myaciadev", SET_RESOURCE, 1, NULL, NULL, "MyAciaDev", NULL,
"<0-3>", "Specify RS232 device this ACIA should work on" },
{ NULL }
};
int myacia_init_cmdline_options(void) {
return cmdline_register_options(cmdline_options);
}
/******************************************************************/
void reset_myacia(void) {
#ifdef DEBUG
printf("reset_myacia\n");
#endif
cmd = 0;
ctrl = 0;
status = 0x10;
intx = 0;
if(fd>=0) rs232_close(fd);
fd = -1;
mycpu_unset_alarm(A_MYACIA);
mycpu_set_int(I_MYACIA, 0);
irq = 0;
}
void REGPARM2 store_myacia(ADDRESS a, BYTE b) {
#ifdef DEBUG
printf("store_myacia(%04x,%02x\n",a,b);
#endif
switch(a & 3) {
case ACIA_DR:
txdata = b;
if(cmd&1) {
if(!intx) {
mycpu_set_alarm(A_MYACIA, 1);
intx = 2;
} else
if(intx==1) {
intx++;
}
status &= 0xef; /* clr TDRE */
}
break;
case ACIA_SR:
if(fd>=0) rs232_close(fd);
fd = -1;
status &= ~4;
cmd &= 0xe0;
intx = 0;
mycpu_set_int(I_MYACIA, 0);
irq = 0;
mycpu_unset_alarm(A_MYACIA);
break;
case ACIA_CTRL:
ctrl = b;
/* TODO: use baudrate for int_acia rate */
break;
case ACIA_CMD:
cmd = b;
if((cmd & 1) && (fd<0)) {
fd = rs232_open(myacia_device);
mycpu_set_alarm(A_MYACIA, ACIA_TICKS);
} else
if(fd>=0 && !(cmd&1)) {
rs232_close(fd);
mycpu_unset_alarm(A_MYACIA);
fd = -1;
}
break;
}
}
BYTE REGPARM1 read_myacia(ADDRESS a) {
#if 0 /* def DEBUG */
BYTE read_myacia_(ADDRESS);
BYTE b = read_myacia_(a);
static ADDRESS lasta = 0;
static BYTE lastb = 0;
if((a!=lasta) || (b!=lastb)) {
printf("read_myacia(%04x) -> %02x\n",a,b);
}
lasta = a; lastb = b;
return b;
}
BYTE read_myacia_(ADDRESS a) {
#endif
switch(a & 3) {
case ACIA_DR:
status &= ~8;
return rxdata;
case ACIA_SR:
{
BYTE c = status | (irq?0x80:0);
mycpu_set_int(I_MYACIA, 0);
irq = 0;
return c;
}
case ACIA_CTRL:
return ctrl;
case ACIA_CMD:
return cmd;
}
return 0;
}
BYTE peek_myacia_(ADDRESS a) {
switch(a & 3) {
case ACIA_DR:
return rxdata;
case ACIA_SR:
{
BYTE c = status | (irq?0x80:0);
return c;
}
case ACIA_CTRL:
return ctrl;
case ACIA_CMD:
return cmd;
}
return 0;
}
int int_myacia(long offset) {
#if 0 /*def DEBUG*/
printf("int_myacia(clk=%ld)\n",myclk-offset);
#endif
if(intx==2 && fd>=0) rs232_putc(fd,txdata);
if(intx) intx--;
if(!(status&0x10)) {
status |= 0x10;
}
if( fd>=0 && (!(status&8)) && rs232_getc(fd, &rxdata)) {
status |= 8;
}
mycpu_set_int(I_MYACIA, myacia_irq);
irq = 1;
mycpu_set_alarm(A_MYACIA, ACIA_TICKS);
return 0;
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.